1. Field of the Invention
This invention relates to devices for testing electrical lines, for example telephone lines, LANs, CATV lines and the like, for faults by time domain reflectometry (TDR).
2. Brief Discussion of the Prior Art
TDR is a well known technique for testing lines in which, for example, one or more electrical test pulses are transmitted into the line at one end thereof, and the voltage on the line at the same end thereof is measured as a function of time after transmission of the test pulse. Any impedance mismatch in the line or at the termination of the other end of the line caused for example by a fault, will cause a reflection of the test pulse to be detected at a time after transmission of the test pulse that corresponds to the position of the impedance mismatch along the line.